A long deep-sea high voltage cable consist of a large number of cable parts which are joined together. The joining process of the cable parts is performed in situ on a cable ship or the like before the cable is laid in the sea. High voltage sea cables have a water tight sheath of lead or copper. The high pressure and the corrosive environment in the deep sea require that the joints between different cable parts have a very good protection. The same requirements apply to cable terminations or cross-connections of cables. It is known to protect the joints, terminations or cross-connections by a casing of a stainless steel material. Such a casing has the required strength to withstand the high pressure and it is resistant to corrosion. However, it is a problem to create a strong and tight connection between a stainless steel casing and the lead or copper sheath of the cable parts.
Stainless steel materials have relatively bad soft soldering properties. It is therefore difficult to make a strong and tight connection between a protective casing of a stainless steel material and a sheath of a high voltage cable by means of a soft soldering process. It is possible to connect a stainless steel casing to the sheath of a high voltage cable by means of a hard soldering process. However, due to the high temperature during a hard soldering process, there is a risk that the heat damages the sheath of the cable or other sensitive components in the vicinity of the hard soldering joint. Especially, in the relatively tough environment on a cable ship, it is difficult to construct a faultless soldering joint by means of a hard soldering process.